The present invention relates to rock crushing systems, such as conical rock crushers or gyratory crushers. More specifically, the present invention relates to a mainshaft bearing retainer for rock crushers.
Gyratory rock crushers generally have a downwardly expanding central conical member which rotates or gyrates within an outer upwardly expanding frustroconically shaped member typically called a shell. The shell can be comprised of two or more pieces, e.g., a top shell and a bottom shell. The central conical member generally has a wearing cover or a liner called a mantle. A spider assembly rests on the top shell, forming the top of the support structure for the machine.
A shaft extends vertically through the rock crusher. This shaft is supported by a bearing in the spider assembly. The central portion of the shaft tapers inwardly in an upward direction to form the central conical crushing member. This portion of the shaft supports the mantle, which moves with the shaft to effect the crushing operation.
The spider assembly is designed to support the shaft while allowing gyratory movement during operation of the machine. Additionally, the vertical position of the shaft is controlled by a piston arrangement in the spider. The piston is slidably disposed within the spider. A bearing is disposed within the piston, and supports the shaft while allowing gyratory motion. The bearing has a hemispherical ball disposed in a socket, lubricated by oil or grease. A mechanical attachment system is required to clamp the ball to the shaft.
In previous designs, the ball has been secured to the shaft using a fastener, such as a nut. The nut is threaded onto the shaft above the ball, which in turn has a hydraulic system used to press the ball onto the shaft. In this type of arrangement, the shaft must extend through the ball to allow the nut to be threaded above the ball. The nut is retained by a bracket system bolted to the top of the shaft.
The conventional mechanical attachment systems are difficult and costly to assemble, repair, and replace because of the complexity of the arrangement. As described above, conventional systems use a hydraulic system to press the ball onto the shaft during assembly and a retainer system to prevent the nut from loosening on the shaft during operation. Further, the threaded shaft is subject to high stress in the area of its threads due to the weight of the shaft and the gyratory motion during crusher operation. Repairs to the shaft can be costly due to the expense of the shaft as well as the expense of the down time necessary to make repairs.
In contrast to conventional bearing retainer systems, it would be advantageous to have a bearing retainer arrangement that may be easily assembled, removed, and replaced. Further, there is a need for a bearing retainer system that does not require threads on the exterior of the shaft of the gyratory crusher. Further still, there is a need for a bearing retainer system that does not require a hydraulic system to assemble the ball and the shaft.
An exemplary embodiment relates to a bearing retainer apparatus. The bearing retainer apparatus is for a gyratory crusher. The bearing retainer apparatus includes a ball, a shaft disposed within the ball, and a plate configured to prevent the ball from moving upward on the shaft. The plate is secured to the shaft.
Another embodiment relates to a gyratory crusher including a shell, a shaft disposed within the shell, and a spider coupled to the shell. A bearing having a ball is disposed within the spider, and a bearing retainer plate clamps the ball to the shaft.
A still further embodiment relates to a method of assembling a bearing retainer system for a gyratory crusher having a shaft and a ball. The method includes steps of providing a bearing retainer plate, providing a plurality of bearing retainer bolts, placing the ball on the shaft, and attaching the plate to the shaft with the bolts. The ball is clamped to the shaft.